Identification of vacuolar phosphate efflux transporters in land plants
Identification of vacuolar phosphate efflux transporters in land plants
复制标题
陆地植物液泡磷酸盐外排转运蛋白的鉴定
DOI：
10.1038/s41477-018-0334-3
复制
发表时间：
2019-01-01
期刊：
影响因子：
18
通讯作者：
Yi, Keke
中科院分区：
文献类型：
--
作者：
Xu, Lei;Zhao, Hongyu;Yi, Keke
无机磷酸盐（Pi）是所有生命形式的重要组成部分。陆地植物通过根和相关的共生体从土壤中获得Pi，然后在整个植物中运输。当足够时，过量的Pi储存在液泡中，用于在Pi缺乏后的再动员。虽然磷从液泡释放到细胞质是植物适应低磷胁迫的一个重要机制，但负责液泡磷外流的转运蛋白尚未确定。在这里，我们确定了一对水稻avacuolar Pi外排转运蛋白（OsVPE 1和OsVPE 2），更丰富的植物生长在Pi缺乏的条件下。这些OsVPE蛋白可以将Pi转运到酵母细胞和非洲爪蟾细胞中。Osvpe 1 Osvpe 2双突变体叶片中的磷含量比野生型高，特别是在低磷胁迫下。在转基因植株中过量表达OsVPE 1或OsVPE 2都降低了液泡中的Pi含量，这与在液泡Pi流出中的作用一致。我们证明，这些VPE蛋白进化从一个古老的质膜甘油-3-磷酸转运蛋白。总之，这些数据表明，这种转运蛋白被招募到液泡膜催化Pi流出过程中的陆地植物进化。
Inorganic phosphate (Pi) is an essential component of all life forms. Land plants acquire Pi from the soil through roots and associated symbioses, and it is then transported throughout the plant. When sufficient, excess Pi is stored in vacuoles for remobilization following Pi deficiency. Although Pi release from the vacuoles to the cytoplasm serves as a critical mechanism for plants to adapt to low-Pi stress, the transporters responsible for vacuolar Pi efflux have not been identified. Here, we identified a pair ofOryza sativavacuolar Pi efflux transporters (OsVPE1 and OsVPE2) that were more abundant in plants grown under Pi-deficient conditions. These OsVPE proteins can transport Pi into yeast cells andXenopus laevisoocytes. Vacuolar Pi content was higher in the loss-of-functionOsvpe1Osvpe2double mutant than in wild type, particularly under low-Pi stress. Overexpression of eitherOsVPE1orOsVPE2in transgenic plants reduced vacuolar Pi content, consistent with a role in vacuolar Pi efflux. We demonstrate that these VPE proteins evolved from an ancient plasma membrane glycerol-3-phosphate transporter protein. Together, these data indicate that this transporter was recruited to the vacuolar membrane to catalyse Pi efflux during the course of land plant evolution.